With 77 seconds left yesterday and the Giants protecting a 27-23 lead, coach Tom Coughlin watched the Redskins take over at their 20, pick up 12 yards on their first play and notch 11 more on their third.

“You’re starting to think, ‘What’s it going to take here?’ ” Coughlin said. “Somehow, some way, somebody’s got to get us a turnover, and thank goodness, that’s what happened.”

Chase Blackburn got that turnover, drilling Santana Moss in the back after his 11-yard gain and stripping the Redskins wideout of the ball at the Washington 43-yard line. Rookie cornerback Jayron Hosley recovered the fumble, ending the Redskins’ potential game-winning drive and sealing the Giants’ first division win.

The Giants defense allowed 248 yards rushing, surrendered 480 total yards and rarely outright stopped the Redskins, who punted once all afternoon. But Blackburn’s forced fumble was one of four huge turnovers the unit caused in the second half, as the Giants picked off Robert Griffin III once and recovered three Washington fumbles. The turnovers only got the Giants seven points, but they probably saved more.

And the final one saved the game.

“We just did our job,” Jason Pierre-Paul said.

The first turnover came on Washington’s second possession of the third quarter, when defensive tackle Linval Joseph knocked the ball away from running back Alfred Morris at the Giants’ 40. Michael Boley recovered it.

A little more than six minutes later, Griffin was intercepted by safety Stevie Brown at the Giants’ 24. Brown ran it back 41 yards, setting up Ahmad Bradshaw’s 1-yard TD plunge. It was Brown’s third pick in the last five weeks, and he has returned each for at least 40 yards.

“Tell you what, he has really come through for us in a big way,” Coughlin said. “Stevie finds the ball or the ball finds him, one way or the other.”

Midway through the fourth quarter, Pierre-Paul caused the third turnover when he sacked Griffin at the Giants’ 30, forcing a fumble that Joseph recovered. Finally, Blackburn struck in the final minutes, initially forcing a fumble on Washington’s first play of its final drive (the Redskins recovered) before forcing his game-clinching one on its third play.